Future challenges for mems failure analysis

Abstract

Abstract MEMS processes and components are rapidly changing in device design, processing, and, most importantly, application. This paper will discuss the future challenges faced by the MEMS failure analysis as the field of MEMS (fabrication, component design, and applications) grows. Specific areas of concern for the failure analyst will also be discussed. 1. Introduction MEMS research is a relatively young field compared to ICs. MEMS design, fabrication, packaging, and reliability testing are still in their infancy and require constant revision and improvements now and over the next several years. MEMS failure analyisis (in this context) is a younger field than MEMS fabrication and design. Although MEMS have been around for a number of years, with failure analysis support for production, packaging, testing, and field operation, the tools and techniques required to properly diagnose the root cause of failure need to be upgraded and designed specifically for MEMS failure mechanisms. MEMS failure mechanisms can be as unique as the devices themselves. In ICs, considerable efforts are taken in handling and testing to properly characterize and assess device performance and compare the performance to device specifications. One major difference between ICs and MEMS testing is the environmental conditions. In many instances, ICs are tested in various environments ranging from various temperature and humidity conditions to vacuum and inert gas. In MEMS technology, similar handling and testing procedures are implemented, but the device is required to work with a given environment [1]. Varying the test environment can dramatically change device sensitivity and functionality. The added complexity of mechanical motion requires added care in handling and testing. Fortunately, MEMS has the advantage of leveraging IC FA tools and techniques for MEMS analysis. However, as the number of devices and applications grow, the MEMS failure analyst must become more diverse and multi-disciplinary in their knowledge base to properly diagnose the root cause of failure. This has become clearly evident in the failure analysis of thermally versus electrostatically driven actuators, microbiological and microfluidic devices, optical and RF components, and the wide array of sensors available for use.